(1) Field of the Invention
The present invention relates to a method and an apparatus for synthesizing speech, in particular, to a method and an apparatus for synthesizing speech in which a text is converted into speech.
(2) Description of the Related Art
Speech synthesizing methods for synthesizing speech by connecting speech pieces heretofore use speech in various accent types in a database of speech pieces without paying particular attention the accent types as disclosed in, for example, "Speech Synthesis By Rule Based On VCV Waveform Synthesis Units", The Institute of Electronics Information and Communication Engineers, SP 96-8.
However, if a pitch frequency of speech to be synthesized is largely different from a pitch frequency of a speech piece stored in the database, general speech synthesizing methods have a drawback that a quality of sound is degraded when the pitch frequency of the speech piece is corrected.
An object of the present invention is to provide a method and an apparatus for synthesizing speech, which can minimize degradation of sound when the pitch frequency is corrected.